Enable default_fonts feature for eframe

The project uses eframe with default-features=false, which disables
the default_fonts feature. This means FontDefinitions::default() is
equivalent to FontDefinitions::empty() — no built-in Latin fonts
(Ubuntu-Light, Hack) are available, causing all ASCII/Latin text to
be invisible.

Add default_fonts to the eframe feature list for both platform
targets so the built-in fonts are embedded and Latin text renders.

Author: fjh1997

Cargo.lock

@@ -73,12 +73,12 @@ md5 = "0.7"
 fontdb = "0.23"
 
 [target.'cfg(any(windows, target_os = "macos"))'.dependencies]
-eframe = { version = "0.31", default-features = false, features = ["glow"] }
+eframe = { version = "0.31", default-features = false, features = ["glow", "default_fonts"] }
 tray-icon = "0.19"
 winit = "0.30"
 
 [target.'cfg(target_os = "linux")'.dependencies]
-eframe = { version = "0.31", default-features = false, features = ["glow", "x11", "wayland"] }
+eframe = { version = "0.31", default-features = false, features = ["glow", "default_fonts", "x11", "wayland"] }
 tray-icon = "0.19"
 gtk = "0.18"